and it is one of those nights that can change history. we want to show you the stage, right now, at the university of denver in colorado. it is standing by, awaiting the candidates. 34 days until your voice, your vote. and the abc news political team is right there in that room. david muir and jake tapper, ready for the opening round to begin. so, david, start us off. >> reporter: diane, good evening from the debate hall here at the university of denver. you can see the stage behind me. everything planned right down to the minute tonight. president obama will enter from the right. the governor from massachusetts, governor romney entering from the left. to give you an idea of the setting here, about 1,000 people inside this debate hall, when it starts. look behind the cameras tonight. we're inside a hockey arena that normally seats 8,000 but they've created this intimate setting as tens of millions watch from their living rooms tonight. when president obama and mitt romney walk onto that stage tonight, it will be the first time they've met